An international team of scientists analysed data on the longterm health effects of physical and emotional abuse from a previous study of over 8,000 adults aged 19-97. The original data were used to study instances of physical and emotional abuse and neglect in children, which are referred to a 'Adverse Childhood Experiences,' or ACEs. Those ACEs were found to be statistically linked to depression, drinking, drug use, and other adverse mental health effects in adulthood.
While looking at the old data, the current research team found that spanking, which is not considered an ACE, showed significant links to the same effects as more severe forms of abuse. Now, they're arguing that spanking should be considered an ACE.
Respondents in the old study were asked how often they were 'smacked' during the first 18 years of their life. If a respondent said they were never spanked, or only spanked once or twice, they were coded as 'no'. If they were spanked a few times per year or more often than that, they were marked as 'yes.'
The results showed that children that were spanked had a higher chance of suffering from depression, making a suicide attempt, drinking heavily and using illegal drugs, compared to those who weren't spanked.
The researchers do not suggest that spanking is equivalent to a more severe form of abuse, but that spanking may be part of a slippery slope of violence and abuse that can cause adverse mental health effects in adults.
That doesn't mean that every child who was spanked is going to be a heavily depressed drug user, or that spanking will definitely cause mental health repercussions. However, they note that there are no scientific studies that show that spanking benefits a child's development or mental health.